Uncovering the relationship between the surface structure and magnetic resonance relaxivities of iron oxide nanoclusters is key to improving the contrast specificity and expanding applicability of this class of contrast agents. The surface properties of iron oxide nanoparticles have enormous effects on the overall magnetic characteristics that determine the particles' relaxation properties. The symmetry at the iron oxide surface is reduced for the chemical surroundings of magnetic metal cations due to the incomplete coordination sphere, and properties of the nanoparticle surfaces are usually different from those within the body nanoparticle. As the size of nanoparticles decreases, the influence of surface interactions magnetic properties of the nanoparticles becomes more significant due to the increased fraction of surface atoms within the particle. Additionally, the coating properties can modulate surface access of water molecules, the particle hydrodynamic size, tumbling rate, solubility, microscale clustering, tissue uptake, and/or intracellular partitioning. However, due to the lack of a model system that has vigorous controls of both its surface core characteristics, detailed investigations of the relationships between structural parameters surface and the relaxivities of iron oxide nanoparticles are still limited. We believe that dendron protected iron oxide nanoparticles can be developed into a novel model for systematically the surface effects on MR relaxation properties. The synthesis of dendrons will be achieved conventional multiple-step organic syntheses in a controlled, defined, and discrete manner. structure of the shell coatings of dendron-iron oxide nanoparticles can be precisely constructed regulated. In addition, due to their dendron coatings, dendron-iron oxide nanoparticles unique class of contrast agents offering many potential advantages over conventional counterparts. For example, when injected intravenously, the leakage of dendron-based the bloodstream into other bodily compartments can potentially be tuned by varying the molecular weight, coverage, and functionality of the dendrons. Our AREA (R15) grant application has set up two specific aims: (1) developing new routes for constructing dendron-coated iron oxide nanoparticles that have various surface electrostatics and other properties; and (2) examining the NMR relaxation-inducing properties dendron-iron oxide nanoparticles in bulk and cellular environments, particularly regarding effects. We believe that this medium-sized R15 grant would be a high-value investment for an important area that has not received much attention from the MR community. [unreadable] [unreadable] [unreadable]